An Access Point Name (APN) is a data structure that typically identifies an Internet Protocol (IP) packet data network (PDN) that a communication device wants to communication with. In addition to identifying a PDN, an APN is also typically used to define a type of service that is provided by the PDN. For example, an APN may be used in a 3GPP data access network, e.g., general packet radio service (GPRS) or evolved packet core (EPC), to identify a connection to an IP Multimedia Subsystem (IMS), a messaging service center (e.g., a Multimedia Messaging Service Center (MMSC)), a wireless application protocol server (WAP), the Internet, a company intranet, an application server, or another device, node, and/or service.
In addition to the PDN from which to provide the user's IP address, an APN is also typically used to select a Gateway GPRS Support Node (GGSN) from which the PDN is accessible. The GGSN provides connectivity between one or more PDNs and the operator's packet domain network. In general, a user accesses a PDN via a GGSN, which may be located in a visited operator's network or may be located in the user's home operator's network. In some circumstances, inter-operator networks provide IP connectivity between operators' packet domain networks.
APN resolution is the process of Domain Name System (DNS) lookup to determine the IP address of the GGSN that provides connectivity to the PDN identified by the APN. When a GPRS communication device sets up a data connection, it provides the APN to which it wants to connect to. APN resolution is then used to select the GGSN and provide an IP address of the GGSN which should serve as the access point. At this point, a packet data protocol (PDP) context can be activated to provide a packet data connection.
An APN may be public or private. A public APN is used for a connection over the public Internet, whereas a private APN is used for a dedicated private connection. Private network connections may be used to provide subscribers with application services via a cloud computing network.
Currently, each private APN is dedicated to providing one application service for a subscriber device. As the number of application services desired by subscribers grows, the number of private APNs needed to provide the application services becomes harder to manage and implement.